This study is intended to support and expand a program of monitoring numbers and immunological reactivity of lymphocytes in patients with neoplasms presenting for radiation therapy. It is generally accepted that immune responses, indicated by measurement of 3HTdR incorporated into stimulated lymphocytes, may be significant in the control of malignancies. To gain insight into the role of patient immunity, as it relates to radiation therapy, patients with different types of neoplasms are being tested before and during follow-up examinations after radiotherapy to determine degree and importance of lymphocyte depression. The depressive effects of radiation are to be related to clinical stage, site of neoplasms, volume of tissue treated with radiation, treatment modality, and prior treatment with surgery or chemotherapy. Of particular significance is whether lymphocyte responses, before or after radiotherapy, are related to recurrence, metastasis or longevity for the patients. To assess responses, whole-blood cultures prepared from peripheral blood are stimulated with mitogens and antigens and the degree of stimulation is assessed by measurement of incorporated 3HTdR. Assessment of immunological responsiveness before initiation of treatment, during treatment, or shortly after treatment may provide a means of estimating clinical course for certain patients with cancer.